There are several opinions:
Rashi - They are to be understood as "שרים" - officers
Ibn Ezra - they are "כוכבים" - stars
The Targum draws the same conclusion as you that they are "כַתֵּי מַלְאֲכַיָא" - groups of angels. This view is also upheld by Metzudas Dovid
Metzudas Zion looks at this language of "אלים" which ...